How To Know If My Betta Fish Is Sick? (11 Signs)

Bettas are one of the most popular freshwater tropical fish that every aquarist love to keep as a pet. Also, bettas are not that demanding and can live in a wide range of water conditions, thanks to their hardy nature. 

However, it becomes a matter of concern when our fish starts to show behavioural changes and changes in their appearance. This time we think if our betta fish is sick or going through any issues. Don’t worry; you have come to the right place as in this article, we will discuss all the signs that betta fish show when suffering from illness and other issues. So, How To Know If My Betta Fish Is Sick? Let’s find out. 

All these signs help us to know if our betta fish is sick and suffering from illness:

  1. Loss of appetite
  2. Clamped fins
  3. Appearing skinny
  4. Hiding most of the time
  5. Staying at the bottom of the tank.
  6. Staying at the top, gulping air.
  7. Fading of colours
  8. Damaged fins
  9. Rubbing against plants, substrate, and decors
  10. Strange swimming pattern
  11. Lethargy

This article will also discuss the common illness your bettas can go through and its signs, causes, and treatment. So, let us get into it and find every solution to your problems.

How to know if my betta fish is sick?

There are many signs that your betta fish shows when they are suffering from illness and other issues.

The very easy signs to detect when to know if your betta is suffering from illness are loss of appetite, lethargy, change in appearance, and damaged fins.

A healthy betta will always be interested in eating as soon as you provide food to them.

Also, a healthy betta always swims around as they are active swimmers.

So, if you find your betta fish sitting at one spot and completely avoiding eating, something is wrong.

There are many other signs your betta fish shows when suffering from illness. Let us talk about all the signs thoroughly.

11 signs betta fish shows when they are sick?

These are the ten signs that your betta will show when they are sick and dying:

  1. Your betta fish will stay at the bottom of the tank most of the time.
  2. Your betta will remain at the surface, gulping air most of the time.
  3. Your betta fish will become lethargic.
  4. Your betta fish will start avoiding eating.
  5. The colours of your betta fish will begin fading.
  6. Your betta fish will have clamped fins.
  7. Your betta fish will have damaged fins.
  8. You will notice the strange swimming pattern of your betta fish.
  9. Your betta fish will appear skinny.
  10. Your betta fish will try to hide most of the time.
  11. Your betta will rub itself against the rock, plants, or substrate.

Stay at the bottom

A sick betta will not be much interested or will not be able to swim. 

You will usually find them at the bottom of the tank sitting in one place.

Bettas are active swimmers, and showing such behaviour is a sign of sickness in betta fish.

Stay at the top, gulping air.

Betta constantly stays at the surface and breathes when a breathing issue occurs with your betta fish.

Yes, bettas come to the surface to breathe air from their mouth as they got a labyrinth organ which allows them to breathe air from the water’s surface.

But, constantly breathing from the surface is not usual, showing that your betta is facing breathing issues.


A sick betta will not be much interested in moving and swimming from one place to another.

They will become lazy due to a lack of energy and stress. 

Your sick betta will spend most of the time in one spot. 

Avoid eating

A sick betta will lose its appetite and will start avoiding eating.

Check for the eating behaviour of your betta fish. 

If your betta fish is not eating like they regularly do or has been stopped eating altogether, there is an issue.

Colours will start fading.

A sick betta will start losing its colour and will look pale. 

It happens especially with male betta fish. 

If you notice any change in your betta fish appearance, there is an issue. 

However, you must know that bettas start getting darker in colour as they grow old. So, make sure that is not the case. 

Clamped fins

There can be two reasons for your betta fish to have clamped fins. 

One is your betta fish suffering from some issues that are causing stress to them, and the second is old age. 

Poor water conditions, inadequate water temperature, bullying, and incompatible tankmates can stress out your betta fish, which can result in betta fish having clamped fins.

Also, an infection can cause clamped fins in your betta fish.

However, old age can also be the reason, so if your betta fish is 2-3 years old, then age can be the factor behind clamped fins.

Damaged fins

A healthy betta fish will have flowing fins without any holes or spots.

So, bacterial or fungal infections are the reason if your betta has damaged fins like rotted fins.

There can be other reasons behind your betta fin loss or damaged fins, the primary reasons being poor water conditions, injuries, and inadequate living conditions.

Strange swimming pattern

When your betta fish is sick or stressed, it will show a strange swimming pattern.

Your betta will struggle to maintain its buoyancy and struggle to swim. Swim bladder disorder can be the reason here.

Stress can also be the reason for the strange swimming pattern in your betta fish.

However, you must know that too much stress makes your betta fish vulnerable to diseases like dropsy and fin rot.


A sick betta will become weak because of the loss of appetite and stress, making them look skinny.

However, if your betta fish suffers from bloating or constipation, it will appear swollen.

Overfeeding can be the reason behind your betta swollen belly.

Hiding most of the time

A sick betta fish will be under constant stress. 

A stressed betta will find a hiding spot and will hide most of the time to relax.

Also, bettas hide when they feel weak, and other fish are in the tank. They hide in such cases to protect themselves from the other fish and hide their vulnerability.

 So, if your betta fish is hiding most of the time, there is something wrong going on. And if the reason is stress, your betta will be vulnerable to diseases. 

Rub against plants, rocks, or substrate.

Your betta fish will rub against the plants, substrate, or rocks when they feel itchy.

It happens when your fish is infected by external parasites, causing itchiness in their skin.

If not treated early, it can also make your betta fish pass away in the worst cases.

What to do if my betta fish is suffering from illness?

The first thing here is to detect what is going on and from what your betta fish is suffering.

And to know that, you must be familiar with the types of illnesses your betta fish can go through and how to treat such.

Let us discuss the common issues your bettas can suffer from throughout their life:

  1. Fin rot/Clamped fins
  2. Swim bladder disorder
  3. Dropsy
  4. Coloumnaris
  5. Constipation
  6. Velvet
  7. Ich/Ick
  8. Tumour
  9. Popeye
  10. Hole in the head

Fin rot/Clamped fins

Fin rot or tail rot is the most common disease in betta fish. 

However, your betta’s fin or tail can also get affected due to biting, boredom, and injury through sharp objects present in the tank.

If your betta fish is suffering from fin rot, then these signs will help you identify it:

  1. White, black, or brown on the fins, tail, or all over the body.
  2. Uneven edges due to fin rotting.
  3. Torn fins and tails
  4. The skin of the fins and tail will appear bloody.
  5. Your betta will become weak and lethargic.
  6. Your betta will lose its appetite.

The cause of fin rot in your betta fish is infection with bacteria. If your betta fish is under stress, then it will be vulnerable to such issues due to a weak immune system.

Treatment of fin rot 

First, you must quickly change 60% and add conditioned water to your betta tank.

After that, clean your betta tank’s substrate to eliminate excess debris and other waste.

Remove the carbon filter and maintain the water temperature between 78-82 °F.

Treat your betta fish with the medication as per the severity of the disease. (A minor fin rot can be treated by just performing the water change and keeping the tank clean, a major fin rot can be treated by salt medication, and a severe fin rot which is also known as body rot, will require an antibacterial and antifungal medication)

Make a 100% water change every time you dose the water with medication.

To know the treatment in detail, you can check out my article How Do You Treat Fin Rot In Betta Fish?

Swim bladder disorder 

Swim bladder disorder causes your betta fish to lose the ability to maintain its buoyancy.

Overfeeding, genetics, and bacterial infection can cause swim bladder disorder in your betta fish.

Your betta fish will have a distended belly and find swimming hard when suffering from swim bladder disorder.

Treatment for a swim bladder disorder

Fasting your fish for 2-3 days and then starting by feeding them with fibre-rich food will help treat swim bladder disorder if constipation is the reason behind the issue.

For more details, you can read my article How To Treat Constipation In Betta Fish?

If bacteria and parasites are the reason behind swim bladder disorder, then antibacterial treatment is necessary.

For knowing the complete details of the treatment of swim bladder disease, you can read my article How To Treat Swim Bladder Disease In Betta?


Dropsy can be stated as a condition rather than a disease. 

It is a condition in which fluids build up inside the body tissue of a betta fish.

Your betta’s stomach will get swollen, and the scales of your betta fish will stick outside.

Treatment for dropsy

Follow these steps to treat dropsy in your bettas:

  1. Arrange a quarantine tank. (A small tank of 5-gallon will be ideal)
  2. Set up the quarantine tank by adding conditioned water, a heater, and an air pump.
  3. Consider creating hiding spots in the quarantine tank so that your betta fish can hide, and also it will help reduce the stress level.
  4. Now add aquarium salt to the quarantine tank by reading the instructions on the back of the aquarium salt.
  5. After setting up the quarantine tank, it’s time to place the sick betta into it. (Place a betta fish in a plastic bag with water from the main tank and float that bag in the quarantine tank for 20 mins before placing the betta into it)
  6. After this, you can start cleaning your main tank by performing a water change and cleaning a filter, glass, and substrate.
  7. Your sick betta will require an antibiotical treatment, and for that, you have to treat your betta fish with amoxicillin to treat them. How and how much to use will be mentioned by the manufacturers. 
  8. It is necessary to perform a daily water change since you are using antibiotics and aquarium salt to treat your betta fish. Ensure you don’t dose the medicine in the same water daily, as it will result in overdosing. This is why water change daily is necessary.


Columnaris, known as the cotton wool disease, is a fungal infection common in tropical freshwater fish.

This comes from the bacteria, which can easily spread and become fatal if not treated early.

High bioload, overcrowding, poor water quality, unstable water parameters, and poor diet can cause columnaris.

Signs of columnaris in your betta fins include frayed or ragged fins, sores on your betta fish skin, White growths on your betta fish mouth and gills appearing like cotton or cloudy. 

At last, you will notice a change in your betta fish gills’ colour as it will appear dark brown. 

The behavioural change includes having trouble breathing and will do rapid breathing to get the oxygen in.

Treatment for columnaris in your betta fish

Follow these steps to treat columnaris in your betta fish:

  1. The very first thing you should do is quarantine your betta fish in a separate tank. (A 5-gallon tank is advisable as it will be easy to treat a sick betta in a small tank)
  2. First, fill the tank with conditioned water and ensure there is nothing in the tank from which your betta can hurt itself.
  3. Columnaris thrive in warm water, so set the water temperature at 75 °F.
  4. After completing the set-up and maintaining the water temperature, treat your sick betta with antibiotics. 
  5. You should go for Furan 2. Read the manufacturer’s instructions properly before using the medicine.
  6. You can use aquarium salt to strengthen your betta fish’s immune system and reduce stress. One teaspoon of aquarium salt per 5-gallon water is ideal.
  7. Make sure to constantly perform a 100% water change, redosing the medication and aquarium salt. 

You can also use Furan 2 and Kanaplex together. But doing this will require more water change. 

If your betta fish is not recovering, use strong antibiotics like Kanamycin.


Constipation is when it becomes harder to pass stools. This happens because of the hard faeces. 

Causes of constipation include a poor diet, overfeeding, swimbladder disorder, and lack of exercise.

Symptoms of constipation include lethargy, stringy faeces, bloated belly, and trouble swimming.

Treatment for constipation in your betta fish

You can treat constipation using Epsom salt, and for that, follow these steps:

  1. Arrange a clean container and fill some tank water. 
  2. Add one teaspoon of Epsom salt per 5-gallon of water into the container water.
  3. Stir it well until it dissolves entirely in the water. 
  4. Add the solution back to the tank. 
  5. Keep your betta fish in a tank with Epsom salt for a week or until you see recovery.

Separate the sick betta and place it in a quarantine tank if you keep it in a community tank. 

For more details on how to treat constipation in your betta fish, you can read my article How To Treat Constipation In Betta Fish?


Velvet, also known as Gold Dust Disease, rust, and Coral Disease, is caused by the parasites in the tank water.

Symptoms of velvet disease in your betta fish include fish covered with gold rust or dust, cloudy eyes, fins closed to the body, lethargy, change in behaviour, and loss of appetite. 

So, velvet can be the reason if your betta fish shows more of the abovementioned symptoms.

Treatment for Velvet Disease in betta fish

These are the things you can do to treat velvet disease in your betta fish:

  1. Raising the water temperature: The parasite that causes velvet disease will be unable to live in warmer water temperatures. So set the water temperature between 83-85 °F. Make sure to increase the temperature slowly, as a drastic change in water temperature will worsen the case rather than recover.
  2. Dim the tank while treating: The parasites contain chlorophyll in their cells and use photosynthesis. So, dimming the tank will eliminate this issue.
  3. Use aquarium salt: Using aquarium salt will help your fish recover. Use one teaspoon per 5 gallons of water. 

In major cases, you must use medications like copper and malachite green. 

While using copper, make sure the water pH level is not low, as when the water pH is below 6.4, the copper will start killing the bacteria that eliminates ammonia and nitrite from the tank.

Copper is not good for invertebrates and plants, so make sure you shift your sick betta in a quarantine tank. 

Malachite green is also a good option to go for. Make sure to use a quarantine tank to treat your sick betta with malachite green, as this medicine will stain things in your tank. 

Read the instructions of the manufacturers and perform the treatment according to that. 

Keep the medication until the instructed time, whether your fish recovers or not.


Ich or white spot disease is a common disease caused by external parasites.

The name of that external protozoan parasite is Ichthyophthirius multifiliis.

Bettas can be vulnerable to diseases like ich when stressed and weak.

Symptoms of ich in your betta fish include white spots all over the body, Rubbing against rocks and plants, lethargy, hiding behaviour, and sudden flashing. 

Treatment of Ich includes salt and water treatment, heating treatment, and treating with medication.

For details about treating ich in your betta fish, you can read my article How To Treat Ich In Betta Fish?


Tumour is very rare on bettas. However, if your betta fish is suffering from a tumour, there is nothing much you can do as there is no cure for the tumour.

Betta fish develop a lump under their skin. The lump size can vary; some can be big, and others can be small.

Causes of tumours include poor water conditions, poor diet and inadequate feeding. 

Also, in many cases, bettas are predisposed to tumours, and you can do nothing about it.

In such a case, you can only provide your betta with a quality life by providing good water conditions, adequate water parameters, and high-quality food.


Popeye is a condition in which your betta fish eyes become swollen or bulge.

Injury or infection can be the reason behind Popeye in your betta fish.

If your betta fish one eye is swollen or bulged, injury can be the reason.

Sharp objects like decors or plastic plants can injure your betta fish.

Replace such sharp objects with smoother ones like live aquatic plants.

Also, ensure no bullying and fighting happen in your betta tank if your betta is living in a community tank with other fish.

However, if both of your betta fish eyes are affected, an infection can be the reason.

Bacterial and fungal infection is the common cause behind Popeye.

If your betta is living in a community tank and other fishes are too showing the signs of Popeye, infection is the reason.

Look for other symptoms like illness, hiding, and loss of appetite.

Treatment of Popeye in betta fish

If an injury is a reason behind Popeye in your betta fish, moving them to a separate tank where no hard or sharp object is present and letting them calm and heal independently is all you can do.

If the infection is the reason, using antibiotical and antifungal medicine will help you cure your betta fish.

Melafix will help you cure your betta fish. Make sure to read the instructions before using the medicine.

Hole In The Head

Hole In The Head is a disease in which fish get holes in their head. However, for now, there is no explanation for the cause of such a disease.

Once you know the cause of the disease, it becomes easier to treat the issue. 

Now, these are some causes that people have found for Hole In The Head:

  1. Poor water conditions
  2. Unstable water parameters
  3. Lack of vitamins
  4. Hexamita

Symptoms include a hole in the head, white stringy faeces, and loss of appetite and colour.

Treatment of Hole In The Head In Betta Fish

Treating is not that easy for such issues in your betta fish. 

However, maintaining the water conditions, ensuring adequate and stable water parameters, and feeding high-quality food will help treat such issues.

Metronidazole is the top pick for treating Hole In The Head if we go towards the medication.

Make sure to place your betta in a quarantine tank before treating.

Take a recommendation from your pet veterinarian before using this medicine.

How to provide ideal living conditions for my betta fish?

Providing your betta fish with their ideal living conditions will completely prevent them from illness and any other issues.

They will remain healthy and will live happy and comfortable life.

Now, ensuring all these things will help you provide your betta fish their ideal living conditions:

  1. Provide your betta fish with ample space. (A minimum of a 5-gallon tank we suggest for a betta fish)
  2. Perform a weekly water change of at least 30% to keep the water clean from excessive waste and harmful toxins.
  3. Treat the water using a water conditioner before adding it to your betta tank to dechlorinate it.
  4. Add a heater to your betta tank to ensure stable water temperature and maintain the water temperature between 78-82 °F.
  5. Maintain a water pH level between 6.5 and 8.
  6. Add a filter with biofilter media to keep the water clean and protected from harmful toxins like ammonia and nitrite.
  7. Add an aquarium light to your betta tank to keep them active during the daytime. (keep the lights off during the night as your betta have to rest at night)
  8. Feed your betta fish with high-quality food regularly. (Feed them two to three pellets or any other food at a time for twice a day to ensure adequate feeding)
  9. Add plenty of live aquatic plants to your betta tank as it will keep the tank well oxygenated, and it is also a good hiding place for your betta fish.
  10. Create hiding spots in your betta tank by adding decors like terra cotta pots, sunken ships, and caves.
  11. Perform monthly maintenance of your betta tank by cleaning the filter, glass, and substrate.


Betta fish shows signs when they are suffering from illness and having issues.

Some common signs are loss of appetite, sitting in one spot and lethargy.

Other signs include clamped fins, damaged fins, appearing skinny, and staying at the top of the tank, gulping air.

It is necessary to find the illness’s actual reason and treat it accordingly.

Some common diseases your betta fish can suffer from are Ich, Columnaris, Constipation, Swim bladder disorder, Dropsy, and Velvet.

Ensuring good water conditions, adequate and stable water parameters, feeding high-quality food regularly, and a stress-free environment will help you prevent most of these issues.

Reference: NCBI, Core.Uk, Wikipedia

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